Climate Change May Continue for a Millennium, Researchers Say

Climate change may be unstoppable for the next millennium, researchers said.

Rising carbon-dioxide levels in the atmosphere will affect the climate for at least another 1,000 years, based on a simulation by researchers at Canada’s University of Victoria and University of Calgary. That will cause the West Antarctic ice sheet to collapse by the year 3000 and raise sea levels by 4 meters (13 feet), it showed.

The study, published online in Nature Geoscience, is the first full climate model to make predictions so far into the future, the Calgary university said in a Jan. 9 statement. Researchers studied the length of time needed to reverse climate-change trends if the world stopped using fossil fuels and putting CO2 in the atmosphere as of 2010 and 2100.

“Ongoing regional changes in temperature and precipitation are significant following a complete cessation of carbon-dioxide emissions in 2100, despite almost constant global mean temperatures,” researchers led by Nathan P. Gillett at the Victoria university said.

The effects’ duration may be related to inertia in world oceans, with parts of the southern Atlantic Ocean beginning to warm only now as a result of CO2 emissions in the previous century, according to the researchers.

“The simulation showed that warming will continue, rather than stop or reverse, on the 1,000-year time scale,” Shawn Marshall, a geography professor at the University of Calgary, said in the statement.

The Northern Hemisphere is better off in the computer simulation, with climate-change patterns reversing in the timeframe in places including Canada, the study shows.

Parts of North Africa would experience desertification as land dries out by up to 30 percent, according to the researchers. Ocean warming off Antarctica of up to 5 degrees Celsius (41 degrees Fahrenheit) is likely to trigger “widespread collapse” of the West Antarctic ice sheet, the study shows.